Actual BC of Berger bullets???

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by trader388, Jan 20, 2005.

  1. trader388

    trader388 Well-Known Member

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    Just curious as to how close the real BCs are to the stated BCs that Berger puts out. Namely the 30cal 210grain @ .640.

    Also BC changes with speed...What velocities are the .640 based on?

    Any other insightful points would be appreciated!
     
  2. goodgrouper

    goodgrouper Well-Known Member

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    I have tested the .264 140 grain Berger VLD at my local shooting range which is about 5000 ft. elevation. Berger rates that bullet at .627 and my testing of bc at 500 yards was .704. I talked to another fellow awhile back that said the 210 VLD measured something like .690 at about 3000 ft. elevation. He was shooting a 300 Wby.
    Berger rates their bullets at a range in California which is somewhere around 1000 foot elevation so if you are close to that elevation, your bullets should be close to the same. I say close because there is literally 100 reasons for bc's to differ. I will list a few just for kicks and giggles.

    1. elevation
    2. humidity
    3. ambient air temp
    4. speed
    5. ogive length
    6. wind direction
    7. bullet jacket condition
    8. barrel condition
    9. barrel vibration
    10. air density/barometric pressure
    11. stability/correct twists
    12. number of grooves in barrel

    And there are many other factors which get real technical.
    So, as you can see, the factory rating is just a starting point. You could have a higher or lower bc!
    Good shooting. --goodgrouper /ubbthreads/images/graemlins/grin.gif
     

  3. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Ttrader388

    I would second what Goodgrouper has posted. I will also say that for extreme range shooting, I have yet to find a manufacturer supplied B.C. that was right on the money and that is due to many of the factors that GD posted.

    ITs just impossible to put a single number on B.C. that works all the time.

    But, I will also say, bullet makers like Berger and even Sierra tend to offer B.C. values that are much more accurate then many of the other big bullet makers. I have found the Nosler B.C. values to be highly overrated at times. Have seen the same with some of the Hornady listings.

    Seems they used these numbers as a sales pitch but it really raised heel when your starting out a new rifle project with a certain bullet and the B.C. is no where near what is listed.

    They are all just s reference point to start your testing from. Bergers will be very similiar depending on the criteria that will effect B.C. the most, altitude is a big one.

    Good Shooting!!!

    Kirby Allen(50)
     
  4. Mikecr

    Mikecr Well-Known Member

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    I wouldn't say it's impossible to state a bullets BC correctly. If qualified by standard conditions, it can calculated from measurements alone.
    Although it will never be that from our guns in the field, a comparison to some standard from one bullet maker to the next would be helpful. But there seems too many standards(which is the same as none). And I have yet to see 2 lots of bullets measure the same.
    Custom bullet makers are consistant as heck. Only in lot though. The next batch will be different, and most custom makers do not post BC at all.
    So it's a gamble really. If you find a great bullet, buy as many as you can or can't afford!
     
  5. brian b

    brian b Well-Known Member

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    This is an interesting topic ,I think that no bullet Co. is exactly on there B.C.s for a lot of the variables that goodgrouper stated but from my experience Berger might be a little more optomistic than sierra on B.C.s. Case in point: I have a 6mm-284 8"twist that I only shot berger 105grVLD's out of it ,the problem was that only 4 out of five was making it to the target with the fifth blowing up past the muzzle (a possible problem with a 3 land barrel) I switched to the sierra 107 gr mk shooting the same charge of RL22 and the velocity dropped off slightly but the point of impact was exactly the same at 1000yds as my previous Berger loads. one bullet claims .565 one claims .525 B.C.
    I think a little bit of tinkering is in order no matter what you shoot.
    b